Selector switch



March 16, 1948. F. EDGARTON SELECTOR SWITCH Filed April 21, 1945 4Sheets-Sheet 1 INVENTOR- FRfi/VK EQGH/PTON BY A9 March 16, 1948. I F,EDGARTON 2,438,042

SELECTOR SWITCH Filed April 21, 1945 4 Sheets-Sheet 2 HTTORNEY March 16,1948. EDGARTON 2,438,042

SELECTOR SWITCH F 3 Q O [:ZEZIZEEEEEE:

HTTOR/VEY March 16, 1948. F. EDGARTON SELECTOR SWITCH Filed April 21,1945 4 Sheets-Sheet INVENTOR. PIP/7AM Patented Mar. 16%, 1948 SELECTORSWITCH Frank Edgarton, Rochester, N. Y., assignor to Stromberg-CarlsonCompany, Rochester, N. Y., a corporation of New York Application April21, 1945, Serial No. 589,667

18 Claims. (01. ne -21.5)

This invention relates to selecting mechanisms and particularly toselecting switches.

The present selecting mechan sm is of the type referred to in the art asa ball selector. In such a selector, a ball is advanced by aprogressive, step-by-step motion, to any desired position along apredetermined path to effect one wanted selection from several possibleselections. Such a selector is especially adapted for use in telephonesystems and the like, wherein rapidity of selection and reliability ofoperation over long' periods of service, are essential.

The main feature of the invention relates to a ball selector of suchconstruction and having such mode of operation that it affords extremereliability and rapidity of operation.

Other features and advantages of the invention will appear from thedetailed description and claims when taken with the drawings in which:

Fig, l is a side elevation of a single acting type of ball selector ofthe present invention;

Fig. 2 is an exploded perspective view of this selector;

Fig. 3 is a bottom view, Fig. 4 is an inverted side elevation and Fig. 5is a top view, with respect to its assembled condition in Fig. 1, of thelower cam assembly;

Fig. 6 is a view, partially in section, particular:- 1y indicating theoutline of the ball race;

Fig. '7 is a fragmentary showing of a portion of the ball race assemblywith the actuating ball therein and also several of the cam elements projecting into the ball race, this showing being particularly useful indescribing the interaction between the cam elements and the ball foradvancing the ball along the ball race and for forcing the cam elementsoutward from the ball race in succession;

Fig. 8 is a side elevation of a modified form of the invention hereinreferred to as a double acting selector and Figs. 9, 10, l1, l2 and 13are schematic showings useful in describing one cycle of operation ofthe ba 1 race assembly of the double acting selector.

The ball selector of the present invention, in one embodiment, comprisesa mounting base 5 (Fig. 2) on the upper surface or" which there issecured a contact spring assembly 5 comprising stacks of contacts, eachstack of contacts including sets of active spring contacts 8 andinactive contacts 9, the several active spring contacts of a stack beingmovable by a single pusher l0 into contact with their related inactivecontacts. The pushers it are arranged in two generally parallel rows. Onthe under surface of the mounting plate, there is secured mechanism forselectively operating the pushers of the stacks of contact springs, oneat a time in a predetermined order.

In the illustrated form of my invention, the operating mechanismcomprises a magnet made up of two parallelly arranged solenoids 14,adapted when energized to attract an armature 25 against the action of apair of springs 35. The armature, in cooperation with a toggle link 49,moves a swinging operating member having a suitable contact operatingmember of relatively small mass disposed for movement along a guideway,In the drawings there is shown a ball race unit 3! movable against theaction of return springs (Fig. 1) so that the ball race unit oscillatesaway from and toward the mounting base 5 in response to the energizationand deen= ergization of the magnet. The ball race unit ifi= eludes anenclosed, flattened elliptical race or guideway 45 (Fig. 6) in which anactuating ball 4"! (Fig. '7) is adapted to travel, the ball race beinggenerally parallel to the base and being generally coextensive in lengthwith the width of the contact spring assembly 8. The ball race unit andthe contact actuating member or ball 41 therein cooperate with meanscomprising cam elements C of an upper cam assembly as well as the camelements C of a lower cam assembly mounted within the cam assemblysupport 2!]. The cam surfaces of the several cam elements of the uppercam assembly and of the lower cam assembly project into the ball race inthe path of the actuating ball, with the cam surfaces of the upper camassembly in alternate relation with those of the lower cam assembly.Thus, as the ball race unit is oscillated in the manner above--mentioned, first a cam element C of the lower cam assembly and then acam element C of the upper cam assembly will be forced outward in amanner to be described. The contours of the cam surfaces, as will bedescribed. are such that as the cam elements of the upper and lower camassemblies are alternately forced outward in suc cession, the ball 41will be progressively advanced along the ball race 44. The cam elementsC of the upper cam assembly project through openings EU in the mountingplate to operate in succession the several pushers Ill, one of which isindividual to each stack of contact springs in the contact springassembly.

With this general description of the ball se lector, a detaileddescription thereof is in order. The solenoids 14 comprising the drivingmagnet, are mounted in parallel relation in a generally rectangularmounting block 15 with their pole faces extending toward the left sideof the block, as viewed in Fi 2. The left end of the mounting block hasthe outer portions of its upper corner provided with knife edges ii, Theintermediate portion of the upper corner of the block is formed with arectangular projection I8 which is received in a recess 23 in the camassembly support 20 as will be further referred to. The intermediateportion of the lower corner of the block is formed with a rectangularprojection l5 which will be further referred to. At each side of therectangular projection l8 there are provided cut-out portions 59 toafford clearance for a portion 26 of the armature, as will be described.The cam assembly support 20 has its right side fastened by screws 33(Fig. 1) against the left face of the mounting block 15. The right sideof the support 29 is provided with projecting alined knife edges 22having the recess 23 therebetween. At each side of the knife edges 22there are provided cut-out portions 24 to afford clearance for a portion2! of the armature, as will be described. The knife edges 22 aredirected toward the cut-out portions E9 in the mounting block when thisblock and the cam assembly support are bolted together in rigidrelation. When thus bolted together, the projection l8 on the mountingblock extends into the recess 23 between the knife edges 22 on the camassembly support, and the projection IS on the mounting block is held incontact with the lower right surface [3 of the cam assembly support 2!].

The armature 25, which is operated by the solenoids l4 and which servesto oscillate the ball race unit, is provided with two upstanding pairsof arms 26 and 2i. The two intermediat arms 26 are shaped to afiordbearings 28 adapted to receive the knife edges 22 on the cam assemblysupport. The two outer arms 21 of the armature are shaped to providebearings 29 to receive the knife edges H on the mounting block. It willbe understood that the knife edges i? on the mounting block and theknife edges 22 On the cam assembly support 20 are arranged to be inalinement in the assembled selector. However, the bearings 28 and 29 onthe two pairs of upstanding arms 25 and 2'! of the armature are slightlyout of alinement but these upstanding arms are somewhat flexible so thattheir bearings can be sprung into alinement when the armature isassembled between the mounting block and the cam assembly support. Thisarrangement assures that there will be no play in the swinging action ofthe armature. The lower part of the armature is provided with twoopenings 3! through which there freely passes the screws 33 threadedinto the cam assembly support 29 to join said support rigidly to themounting block Hi. The openings 3! are of sufficient size so that thementioned bolts can pass therethrough and yet the armature can oscillatewithout striking these bolts In the lower corners of the left face ofthe mounting block there are provided recesses to receive coil springs35. The outer ends of these springs respectively engage the lower endsof the armature tending to swing the lower portion of the armature awayfrom the mounting block and from the solenoids. The right face of themounting block, as shown in Fig. 1 is provided with hardened inserts 36each having a V-notch therein. These V-notches serve as bearings aboutwhich the ball race unit 3i oscillates,

The ball race unit 31 comprises a generally rectangular frame with oneof its sides interrupted to define inturned end portions 39. Theseportions have knife edges 4%] adapted to engage the V-shaped notches inthe hardened inserts 35. The side of the unit opposite the knife edges iprovided with the ball race 44 (Fig. 6). As shown in cross section inFig. 1, this assembly comprises two plates (52 and d3 secured togetherwith their inner faces in contact. The inner surfaces of these platesare each formed with a depression of generally flattened ellipticaloutline. The two depressions in these plates when brought into registrydefine the ball race 4d of generally flattened elliptical outline and ofa size in cross section to enable the hardened actuating ball 41 (Fig.'7) to travel freely therealong. Each plate has openings therein,generally rectangular in cross section, extending into the race, theopenings 45 in plate "32 being staggered with respect to the openings 55in plate 43. The lower plate as of the ball assembly is provided with aknife edge 43a to cooperate with the V-shaped recess 58 in one side of atoggle link 49. The opposite side of this link is provided with a knifeedge 59 to engage a notch 5! in the adjacent surface of the armature 25.

The carn assembly support 2i has a vertical recess 52 therethroughpositioned directly above and below the ball race when the device is puttogether. The support 20 is provided with an internal ledge 53 on thewall of the recess adjacent the top thereof and asimilar ledge 54(Fig. 1) adjacent the bottom of the support. The upper ledge 53 receivesand supports an upper cam assembly 55, while the lower ledge 54 supportsa lower cam assembly 55. Each cam assembly as shown in Fig. 1 comprisesa main plate 51 having a series of circular openings 58 (Fig. 2)therein, positioned in accordance with a pattern having an outlinesimilar to the outline of ball race M in the ball race unit. The mainplate 5 has secured thereto, in spaced parallel relation, a guide plate59 of similar outline but of smaller dimensions than said main plate.Thus, the guide plate 59 can extend into the opening 52 in the camassembly support to a point beyond its related ledge while the margin ofthe main plate rests on that ledge. As herein shown, the guide plate haslegs Bil formed thereon which can be joined to the main plate by weldingor the like. The guide plate 59 has a series of rectangular openings 6itherein positioned in a pattern similar to the circular openings 58 inits related main plate with a circular opening in the main plate and arectangular opening in the guide plate located in slightly offset-relation. It should be pointed out that the rectangular openings 5!in the upper guide plate 58 have the same pattern as that of the ballrace support in Fig. 2, while the rectangular openings 6| in the lowerguide plate 59 are arranged as indicated at the lower left of thisfigure and in Fig. 5.

The series of cam elements 0, one for each circular opening 58 and forits related rectangular opening Bl are mounted in the two plates 5'! and59. Each cam element, as best shown in Fig. 7, comprises a cylindricalstem 63 of a length to have its inner end contact the guide plate 59 andits outer end to project through the main plate 5's. The outer end ofthe stem, as shown, is solid to engage the pusher It but its innerportion is hollow to receive with a force fit, a portion 66 of a fiatcam, such as 62a which extends through the guide plate 59. The free endof each cam Within the ball race has a generally inclined surface, theinclined surfaces of the several cams face in the direction of movementof the ball 41.

It will be noted that stem 63 of the cam element has a shoulder 68against which one end of a coil spring 6% engages. The other end of thisspring engages the main plate The projecting end of each stem 63 of theupper cam assembly registers with a corresponding opening 70 in themounting base 5 so that each stem when elevated will encounter thepusher iii of a given stack of contact springs.

It will be noted in Fig. 1 that there is mounted on the right side ofthe mounting block, a socalled microswitch l5, namely a switch thatcloses its contacts H5 (Fig. 2) with a snap action. In this switch, whena button 71 thereof is depressed, the switch will snap from one positionto the other and when the pressure is removed from the button, thecontact springs will snap back to their original position. The button I!(Fig. l) of this snap switch is actuated by a push rod 19 adapted tomove longitudinally through a guide in the mounting block under theaction of armature 25 and a suitable return spring (not shown). Thispush rod '39 at its left end, is pointed to engage a tapered recess 8!located at an intermediate point on the armature 25. The other end ofthe push rod contacts button Ti.

The upper surface of the mounting block it, is provided with a recess toreceive an insulating plate 82 and the terminal strip 83 of insulatingmaterial. The strip 83 has mounted thereon, the terminals 86. Theseterminals are electrically connected to the windings of the solenoidsand to the snap-acting switch it in the well-known manner. The exposedends of the terminals 8!) are for the purpose of external circuitconnections.

In the operation of the selector switch, it will be understood that acircuit is completed, through the microswitch it or not, depending uponcircuit considerations, to energize the two solenoids M of the magnet.When energized the solenoids attract the armature 25 which oscillates onthe knife edges I1 and 22. As the armature is attracted toward thesolenoids, the toggle link 49 tends to move toward the right (Fig. 1),but in so doing, knife edge support &8 of the toggle link will alwaysremain higher than knife edge 50, thus insuring that the toggle linkwill never assume dead center position. The return spring 85 normallyurges the ball race unit 31 downward so that when the toggle link (itmoves toward the right, the ball race is moved downward. Also, when thearmature 25 is attracted toward the solenoids, the push rod 79 is movedlengthwise toward the right. This movement of the push rod actuates thebutton Ill of the snap-acting switch to change the relation of itscontacts. The operating circuit for the solenoids 14 may be connectedthrough the contacts of thesnap-acting switch to provide aself-interrupting circuit, in the well-known manner. The operatingcircuit of the solenoids will now be interrupted so that they will nolonger attract the armature 25. The coil springs 35 tend to return thearmature 25 to its normal position and the armature during its returnmovement acts through the toggle link to force the ball race unit 37upward against the action of spring 65. The push rod 19 also follows thearmature. This push rod releases the pressure on the button T1 of thesnap-acting switch permitting its contacts to move to their alternateposition. The repeated opening and closing of the snap-acting switchwill continue to energize and deenergize the solenoids M with aconsequent oscillation of the armature 25, until a predetermined circuitcondition is satisfied.

Each time that the ball race unit moves downward the ball 41 in its ballrace 44 is constrained to move downward therewith. During this downwardmotion the cam 62a follows the ball until this cam reaches its normalposition, as indicated by the dotted lines in Fig. 7. However, the ballcontinues downward after leaving the cam 62a so that it promptlyencounters and starts to depress the cam 62b. Cam 62?), while thus underpressure from the ball, imparts a sideWise thrust on the ball with theresult that as soon as the ball has descended far enough to clear thebottom of the cam 620, the ball will be propelled along the ball raceuntil it is in contact with the side of the cam 62d. The ball thencontinues downward until it reaches the lower limit of its motion. Bythis time, the ball has depressed the cam 62b to the position shown indotted lines. As the ball race then moves upward carrying with it theball, the ball is followed by the cam 822) until this cam reaches itsnormal position. The ball then leaves contact with the cam 82b and atonce encounters cam 620 which it then starts to raise. Cam 620 underpressure reacts to impart a sidewise thrust on the ball with the resultthat as soon as the ball has been lifted high enough to clear the top ofcam 6201 it will be propelled along the ball race until it comes intocontact with the side of cam 62c. The ball then continues its upwardmovement until the ball race has reached the upper limit of its motion.At this point, the ball has succeeded in raising cam 620 to the positionshown in dotted lines. In a similar manner repeated lowering and raisingof the ball race assembly in response to further operation of thesolenoids will cause the ball to be propelled along the ball race andlowering and raising succeeding cams until a desired set of contactsprings 8 has been operated. On the release of the switch, the ball racewill continue to lower and raise with the consequent advance of the balland the successive operation of the cams until the ball has completedits entire elliptical course around the ball race to a so-called normalor home position, which may be any one of the stacks of contact springs8, or a special stack designated for this purpose. At this position theoperating circuit for the solenoids will be open. The path of the ball,as it progressively moves along the ball race, in response to thedownward and upward movement of the ball race unit, is indicated in dotand dash lines in Fig. 7 wherein this line represents the locus of thecenter of the ball in the course of its travel during one completedown-and-up cycle of the ball race assembly. From consideration of thispath of travel of the ball, it will be noted that the motion of the ballalong the ball race occurs at a time when the ball is very lightlyloaded due to the spring action against the several cams. However, whenthe ball is depressing or raising a cam far enough to build up or pickup a large vertical spring load, only vertical motion is required of theball.

It should be pointed out that no useful work in actuating a stack ofsprings is performed by any depressed cam while the ball race assemblyis held in its lower position. In the foregoing arrangement, it is notintended to actuate a given stack of springs during the actual durationof the impulses applied to the solenoids. The duration of the impulseis, of course, momentary and with the required armature travel.

for this reason the stacks of springs are all as..- sociated with theupper cams only. At the termination of each impulse the solenoidsdeenergize. The armature springs 35 which have been under maximumcompression during the impulse act with sufficient force to push the,armature away from the magnet poles. It will be noted that the point 68of the toggle link is higher than the edge thereof. Therefore, the forceof the armature spring on the armature is transmitted through the togglelink to cause the ball race assembly to rise against the action of thespring 85. The ball race unit travel is large compared When the ballrace unit rises, it lifts the ball t? into contact with a selected uppercam, which cam is raised and in turn actuates the selected stack ofsprings 8. The ball race assembly continues to rise until the armaturehas been pushed to the limit of its travel or until the back pressure ofthe load of the contact spring stack has equalized the force of thearmature spring. The mechanism remains in this position until the nextimpulse is received. Thus impulses applied to the driver unit aretranslated into actuation of successive stacks of springs 8. For eachenergization and deenergization of the solenoids, a spring stack isrestored to normal and the next spring stack in succession is actuated.The foregoing selector may be referred to as the single action typesince only its upper cams can be utilized for actuating a stack ofcontact springs since each complete impulse causes the ball race unit tobe lowered only momentarily during the impulse of the solenoids and thento be raised again where it remains until the next impulse is received.In this arrangement, the lower set of cams which are required tocooperate with the upper cams in propelling the actuating ball are notused to actuate contact spring stacks.

In the modified form of the invention shown in Fig. 8, the selectorswitch has been changed so that not only the upper series of cams butalso the lower series of cams are each effective in operating a stack ofcontact springs. The parts of this construction which are identical withthose already described are designated by the same reference charactersand will not be further described. In this construction, the armature St consists of an approximately rectangular plate which is slightlyflexible. This armature is reinforced at an intermediate point by ablock 85 having a notch therein to receive the knife edge 5d of thetoggle link the knife edge 58 being located generally at the center lineA-A of Fig. 8. The edge 85a of the armature rests against an upper ledge3? while the lower edge etc of the armature rests against the lowerledge 88. This armature is free to rock on either of the ledges 8? and38 as a fulcrum if the forces acting on this armature permit suchmovement. he armature springs 89 exert their force along the center lineA-A. The ball race unit and the toggle link are so coupled to thearmature that if the ball race is held at the mid-point of its travel,the edges 38 and to of the toggle link as well as the rotational axis ofthe ball race unit will all lie along the center line A-A. The magnetpull is also exerted along this center line. The distance from .8 to 5dof the toggle link is such that when the ball race unit is held on thecenter line, namely on dead center, the armature 85 is caused to bowslightly, as shown in exaggerated form in the diagram of Fig. 11. In theoperation of the selector, the normal positionof the .parts thereof willbe either as indicated in Fig. 9 or in Fig. 13 since the positionillustrated in Fig. 11 is an unstable one.

Let it be assumed that the mechanism is awaiting an impulse with theball race assembly in the upper position in Fig. 9. The armature spring89 is then exerting a force on the armature which, opposed by thedownward load on the ball race unit, transmitted through the togglelink, has caused the armature to assume the position shown in Fig. 9. Inthis position, the upper edge 84a of the armature has been rockedoutward from the ledge 81 by using the ledge 88 as a fulcrum. Thepressure of the strong armature spring 89 serves to hold the ball raceassembly at the top of its travel with a stack of contact springs 8actuated by the selected upper cam. At the beginning of the next impulsethe solenoids are energized. This causes the armature to rock back toits vertical position with the armature edges Ma and 84b respectively incontact with the ledges El and 38, as indicated in Fig. 10. This permitsthe ball race assembly to start downward. The pull of the magnet isinsufficient to bow the armature, but the moving ball race assembly hassufiicient momentum in its travel downward, so that it is enabled toreach and pass through the dead center point, namely the center line A-Athereby bowing the armature slightly in order to pass through deadcenter, as indicated in Fig. 11. As soon as the ball race assembly haspassed through dead center the armature ii -l in relieving itself of thebowing action will thrust and hold the ball race assembly in the lowerposition shown in Fig. 12. The .ball race will remain in this positionuntil the solenoids are deenergized at the end of the impuse. When thesolenoids are deenergized the pressure of the armature spring 89 forcesthe armature outward from the solenoids. Since the ball race unit isalready below the center line AA it will oppose the armature spring insuch a way as to cause the armature edge 8 m to rock on the ledge 87 asa fulcrum, while the armature swings its edge 85b outward. The ball raceunit can now be swung to the lower limit of its travel where it willremain, holding the selected cam and the stack of contact springs toactuated thereby until the next impulse takes place. This condition isindicated in Fig. 13. When the next impulse starts and the solenoids areagain energized the armature 845 will again assume its vertical positionand the ball race unit will rise passing through the phases indi catedin Figs. 12 and 11 and eventually assuming the position indicated inFig. 10 where it will await the end of the impulse.

When the solenoids are deenergized at the end of the impulse, thearmature 84 will be rocked outward on the ledge 38 as a fulcrum, thearmature driving the ball race unit to the upper limit of its travel asindicated in Fig. 9. Thus, the modified selector cf Fig. 8 selects insequence the various contact spring stacks associated with its severalcams making alternate selections from its upper lower cam groups.

What I claim is:

1. In a selector switch having sets of contacts to be operated, a magnetprovided with an armature arranged to move toward and away from saidmagnet in response to the energization thereof, a member movable backand forth under the control of said armature, said member having a ballrace therein, a ball contained in said race, elements projecting intosaid race for progressively moving said ball along said race as saidmember moves back and forth, and means including cer-.

9 tain of said elements for actuating said sets of contacts insuccession under the control of said ball.

2. In a selector switch having sets of contacts to bev operated, amagnet provided with an armature arranged to move toward and away fromsaid magnet in response to the energization thereof, a member movableback and forth under the control of said armature, said member having aball race therein, a bail contained in said race, independently movableelements projecting into said ball race for progressively advancing saidball along said race as said member moves back and forth, and meansincluding certain of said elements for actuating said sets of contactsin succession under the control of said ball as it advances.

3. In a selector switch having sets of contacts to be operated, a magnetprovided with an armature arranged to move toward and away from saidmagnet in response to the energization thereof, a member movable backand forth under the control of said armature, said member having aguidew-ay therein, a contact actuating member of relatively small massdisposed for movement along said guideway, independently movableelements projecting into said guideway from opposite sides thereof forprogressively moving said ball along said guideway as said member movesback and forth, and means including certain of said elements foractuating said sets of contacts in succession under the control of saidactuating member.

4. In a selector switch, sets of contacts arranged in two spaced rows, amagnet provided with an armature arranged to move toward and away fromsaid magnet in response to the energization thereof, a member movableback and forth between said rows under the control of said armature,said member having a guideway therein extending in a plane substantiallyparallel to said rows, a contact actuating member of relatively smallmass disposed for movement along said guideway, individually movableelements projecting into said guideway from opposite sides thereof forprogressively moving said actuating member along said guideway as saidmember moves back and forth, and means including said elements foractuating said sets of contacts in succession under the control of saidactuating member.

5. In a selecting device, a block provided with a pair of knife edgesadjacent one surface thereof, a support adapted to have one of its facessecured in spaced relation to the surface of said block, said supporthaving a pair of knife edges in alinement with the knife edges on saidblock and in side by side relation therewith, an armature provided withtwo pairs of somewhat flexible arms provided with bearings to engagesaid knife edges, said bearings prior to assembling be ng misalined butbeing adapted to be sprung into alinement with each other by engagementwith said knife edges, contact springs, and means including saidarmature for actuating said contact springs.

6. In a ball selector, a series of elements to be operated insuccession, a ball race mounted to move back and forth in a given pathextending generally at right angles to the principal axis of said race,a ball in said race, means for moving said ball race in said path, saidseries of elements projecting into said ball race where they terminatein cam surfaces which are all inclined with respect to the plane of saidrace, and in the same direction with respect to the path of said ball insaid race, and means including said cam surfaces for advancing said ballalong said ball race during the back and forth movement thereof, saidball as it advances actuating said elements in succession.

7. In a selector switch, sets of contacts arranged in two spaced rows, amagnet provided with an armature arranged to move toward and away fromsaid magnet in response to the energization thereof, a member movableback and forth between said rows under the control of said armature,said member having a ball race therein extending along said rows, a ballcontained in said race, individually movable elements projecting intosaid race from opposite sides thereof for progressively moving said ballalong said race as said member moves back and forth, said elementsterminating in said race in cam surfaces which are all inclined withrespect to the plane of said race, and in the same direction withrespect to the path of said ball in said race, and means including saidelements for actuating said sets of contacts in succession under thecontrol of said ball.

8. In a selecting devicea block provided with a pair of knife edgesadjacent one surface of said block, a support adapted to have one of itsfaces secured in spaced relation to the surface of said block, saidsupport having a pair of knife edges in alinement with the knife edgeson said support and in side by sid relation therewith, an armatureprovided with tWo pairs of somewhat flexible arms provided with bearingsto engage said knife edges, said bearings prior to assembling beingmisalined but being adapted to be sprung into alinement with each otherby engagement with said knife edges, two spaced series of elements to beoperated in succession, a guideway mounted to move back and forth in agiven path extending generally at right angles to the principal axis ofsaid guideway, a contact actuating member of relatively small massdisposed for movement along said guideway, means for moving saidguideway in said path, the two series of elements projecting into saidguideway from opposite sides thereof where they terminate in camsurfaces which are all inclined with respect to the plane of saidguideway, and in the same direction with respect to the path of saidactuating member in said guideway, means including said cam surfaces foradvancing said actuating member along said guideway during the back andforth movement thereof, said actuating member as it advancesalternatively actuating an element in one series and then an element inthe second series in succession.

9. In a selecting device, a block member, a support member having a facesecured in spaced relation to a face of said block member, one of saidmembers having a pair of knife edges at its face and the other memberhaving at its face at least one knife edge in alinement with the knifeedges on said other member and in side by side relation therewith, anarmature provided with somewhat flexible arms provided with hearings toengage said knife edges, said bearings prior to assembling beingmisalined but being adapted to be sprung into alinement with each otherby engagement with said knife edges, contact springs and means includingsaid armature for actuating said contact springs.

10. In a selector switch, sets of contacts arranged in two spaced rows,a magnet provided with an armature arranged to move toward andsubstantially at right angles to said rows, means including a togglelink for translating the movement of said armature into the movement ofsaid member in said path, said link having two stable terminal positionsrespectively related to the two rows of contact sets and having anunstable intermediate position, said member having a guideway thereinextending along said rows, a contact actuating member of relativelysmall mass disposed for movement along said guideway, individuallymovable elements projecting into said guideway from opposite sidesthereof for progressively moving said actuating member along saidguideway as said member moves back and forth, and means including saidelements for actuating said sets of contacts in succession underthecontrol of said ball.

11. In a ball selector, a series of elements to be operated insuccession, an element operating member mounted to move back and forthin a given path extending generally at right angles to the principalaxis of said operating member, said operating member having a guidewaytherein. a contact actuating member of relatively small mass di posedfor movement along said guideway, means for moving said operating memberin said path, said series of elements projecting into'said guidewaywhere they terminate in cam surfaces presenting a saw-tooth array alongthe principal axis of said race, means including said cam surfaces foradvancing said actuatin member along said guideway during the back andforth movement thereof, said actuating member as it advances actuatingsaid elements in succession.

12. In a selector, a block having knife edges at One surface thereof, amagnet mounted on said block a support having knife edges proiectingtherefrom, said support being mounted in spaced relation to the surfaceof said block with said knife edges alined with each other in side byside relation, an armature having pairs of arms provided with bearingsrespectively engaging said knife edges whereby said armature can swingtoward and away from said magnet, a, unit having a ball race therein,and mounted to move back and forth in a path generally at right anglesto the direction of movement of said armature, means including saidarmature for moving said unit, a ball in said race, and a plurality ofelements to be selected, individually movable in the general directionof said path, each element having a pointed end biased to project intosaid race in the path of said ball, said ball as it moves with said unitdisplacing said elements in succession, each element as a result ofdisplacement serving to propel said ball along the ball race.

13(In a selector switch, sets of contacts arrangedin two spaced rows, amagn'et'provided with a somewhat flexible armature, arranged to be movedtoward and away from said magnet, in response to the energization anddeenergization thereof, said armature being mounted to rock on either ofits opposite edges, 9, contact operating assembly mounted to swing in apath generally parallel to the plane of said armature, a toggle linkhaving one end engaging an intermediate portion of said armature and itsother end engaging a part of said contact operating assembly, said linkbeing somewhat longer than the distance between an intermediate portionof the armature and said part when the contact operating assembly is inits nearest position to said armature whereby said link will snap fromone position of stability to another through a position of instability,said contact operating assembl having a guideway therein, a contactactuating member of relatively small mass disposed for movement alongsaid guideway, individually movable elements projecting into saidguideway from opposite sides thereof for pro-- gressively moving saidactuating member along said guideway as said assembly moves back andforth in said path, and means including said elements for actuating saidsets of contacts in succession under the control of said actuatingmember.

14. In a selector switch, a ball race mounted for movement back andforth in a given path substantially at right angles to the principalaxis of said race, oppositely disposed Walls of said race havingopenings therethrough, the openings in one of said walls being staggeredwith respect to the openings in the opposite wall, a plurality ofelements to be operated in succession, said elements being disposed intwo sets on opposite sides of said race in the direction of movement ofsaid race, one set being associated with said one Wall and the secondset being associated with said opposite wall and said elements extendingthrough said openings into said race, the inner end of each elementhaving a cam surface, all of the cam surfaces being inclined withrespect to the principal axis of said race and in the same direction, aball in said race, and means for imparting movement to said race wherebysaid elements successively cooperate with saidrace to urge said ballalong said race.

15. In a selector switch, a ball race mounted for movement back andforth in a given path substantially at right angles to the principalaxis of said race, oppositely disposed Walls of said race havingopenings therethrough, the openings in one wall being staggered withrespect to the openings in the opposite wall, a pluralit of elements tobe operated in succession, said elements being disposed in two sets onopposite sides of said race in the direction of movement of said race,one set being associated with said one wall and the second set beingassociated with said opposite wall and said elements extending throughsaid openings into said race, the inner end of each element having a camsurface, all of the cam surfaces being inclined with respect to theprincipal axis of said race and in the same direction, a ball in saidrace, and means for imparting movement to said race whereby saidelements successively cooperate with said race to urge said ball alongsaid race, each of said elements being resiliently urged toward saidrace.

16. In a selector switch having sets of contacts to be operated, a ballrace mounted for movement back and forth in a given path substantiallyat right angles to the principal axis of said race, oppositely disposedwalls of said race having openings therethrough, the openings in onewall being staggered with respect to the openings in the opposite wall,a plurality of elements to be operated in succession, said elementsbeing disposed in two sets on opposite sides of said race in thedirection of movement of said race, one set being associated with saidone wall and the second set being associated with said opposite wall andsaid elements extending through said openings into said race, the innerend of each element having a cam surface, all of I the cam surfacesbeing inclined with respect to the principal axis of said race and inthe same direction, a ball in said race, and means for impartingmovement to said race whereby said elements successively cooperate withsaid race to urge said ball along said race, and means including certainof said elements for actuating said sets of contacts in succession assaid ball advances along said race.

17. In a selector mechanism having contacts to be operated, a movableoperating member having a guideway, means for causing movement of saidoperating member toward and away from said contacts whereby saidguideway is moved toward and away from said contacts, a contactactuating member of relatively small mass disposed for movement alongsaid guideway, means projecting into said guideway for causing movementof said actuating member along said guideway as said operating membermoves back and forth in order to operate said contacts.

18. In a selector switch having sets of con- 14 tacts to be operated, amovable operating member having a guideway, means for causing movementof said operating member toward and away from said contacts whereby saidguideway is moved toward and away from said contacts, a contactactuating member of relatively small mass disposed for movement alongsaid guideway, a plurality of elements projecting into said guideway forprogressively moving said actuating member along said guideway as saidoperating member moves back and forth in order to operate successivelysaid sets of contacts.

FRANK EDGARTON.

REFERENCES CITED FOREIGN PATENTS Country Date Germany July 6, 1935Number

